306 MAZATLAN UNIVALVES 



tion of the shells to rocks and stones, near low water mark 

 of neap tides, not uncommon ; C. IB. Adams. 

 Comp. Verrnetus Panamensis, " Eouss. in CMnu, HI. Conch. 

 pi. 5, f. irMJce. in Zeit. f. Mai. 1850, p. 165, no. 13. 

 C. B. Ad. Pan. Shells, p. 216. no. 324. Hal Mazatlan ; 

 in mass of coral, on Spondylus ; Menlce. Panama ; in the 

 same situations as V. glomeratus, attached on one side of all 

 the whirls ; C. B. Adams. 



This species may possibly be the V. glomeratus of MJce. and 

 C. B. Ad. : but as it is not the S. glomerata of Linn. (v. Hani. 

 Ips. Linn. Conch, p. 444,) nor the V. glomeratus of Phil., which 

 has a peculiar habit of growth, it does not seem fair to adopt 

 the name figured only in Chenu, especially as that appears a 

 third species, judging by the size and colour.* The shell may 

 again prove to be the V. Panamensis of the same authors ; but 

 the figures cited do not appear with that name, but with that 

 of V. lumbricalis, Lam. There can scarcely be a doubt that 

 they represent the species of Adanson "Le Vermet" : as to 

 whether that be the real V. lumbricalis of Lam., v. Desk. An. s. 

 Vert. vol. ix. p. 66, no. 1. Whether this again be the S. lum- 

 bricalis of Linn., v. Hani. Ips. Linn. Conch, p. 445. 



The shell is much more uniform in diameter and more parallel 

 in spire-margins than A. centiquadrus, jun. which it resembles 

 in sculpture, and mode of attachment. The colour is however 

 generally with more of a pink and less of a brown tinge. The 

 nuclear whirls resemble Eissoa. It is known externally from 

 Petaloconchus macrophragraa, which it resembles in mode of 

 growth, by its much ligher colour, without purple tinge. An 

 extremely fine specimen, from the Gulf of California, is in 

 Mr. Cuming's collection. A closely related, if not identical 

 species is found in the W. Indies. Long. '9, lat. apert. '14. 

 Hob. Mazatlan ; not uncommon, on Spondylus, Gadinia, and 



other shells ; L'pool Col. 



Tablet 1489 contains 4 sp. very young. 1490, 1 sp. on frag- 

 ment of Pinna, and several young on Gadinia pentegonio- 



* Or C. B. Adams' V. glomeratus may be the Alete9 centiquadrus, which is 

 cited under query in the Pan. Shells as a synonym. A different species from 



Bri 



taken his synonyms on trust, and copied the species of Menke's Catalogue. Tnis 

 ' at least will explain the confusion. Mr. Bridges' shell was at first believed by 

 Mr. Cuming and myself to be a Petaloconchus, in consequence of the edges of a 

 minute Isognomon appearing inside a broken section. After opening several parts 

 in hopes of observing the structure, the bivalve fell out, and .the Vermetid sub- 

 sided into Bivonia. 



